Biomechanical aspects of spine sagittal balance in patients with coxarthrosis in total hip replacement (preliminary study)

Abstract

The purpose of the study was to evaluate specific features of spine sagittal balance in patients with coxarthrosis of different etiology before and after total hip replacement (THR). Materials and methods Clinical and radiographic evaluation was performed for 46 patients admitted for primary THR. The patients were diagnosed with dysplastic (n = 14), degenerative (n = 26) and posttraumatic (n = 6) coxarthrosis and evaluated preoperatively, on the 7th day postsurgery and at a long-term follow-up. Spinopelvic parameters of sagittal balance, stages of osteoarthritis and cranial displacement of femoral heads according to Crowe were assessed. Clinical evaluation included physical examination, hip function with the Harris Hip Score (HHS), range of motion in the involved hip, relative limb shortening, neurological status, Oswestry questionnaire (ODI) and spinal pain syndrome using the Wong-Baker Faces Pain Rating Scale (2011). A statistical software package of Microsoft Office Excel 2016 was applied for data analysis. Statistical analysis of variance was used to calculate the arithmetic mean (M), error of the arithmetic mean (± m), the Pearson correlation coefficient r and estimate using the Chaddock scale. The Student’s t-test was used to confirm significant differences in the means identifying a significance level. Results and discussion Comparative analysis of spinopelvic parameters showed decreased PT and SS with increased LL in patients with dysplastic coxarthrosis. No considerable changes of spinopelvic parameters were revealed in patients with degenerative coxarthrosis. Marked limitations in ROM were seen in patients with dysplastic coxarthrosis. A moderate correlation between ROM of the involved hip and spinopelvic parameters was observed in dysplastic coxarthrosis. No correlation was detected between spinopelvic balance and spinal pain syndrome. Conclusion No significant differences in spinopelvic parameters were noted in patients with hip-spine syndrome associated with degeneration. Dysplastic changes can be a predisposing factor for spinopelvic imbalance in THR. Correlation analysis showed that combined joint contracture was involved into the biomechanical aspect of spinopelvic imbalance in dysplastic coxarthrosis. As reported by other researchers, total hip replacement with good functional outcome was not shown to result in significant changes in spinopelvic alignment.